After their great victory at the shipyard, Yoshi and Spike move on to the castle at Canterlot, the place where Bowser calls home, for now. Yoshi and Spike went inside the palace, it was much more different to Spike, since he already visited the castle, Bowser had rigged the place, sort of the way the evil King Sombra did it, black crystals shot out at every direction, but they were more reddish.
They searched the castle for their dark enemy, until they found him, Bowser Jr. and surviving soldiers waiting for them, Soon wind started blowing from the broken windows, and Bowser began talking. "BWA HA HA HA!! You finally made it!" No responces came from what Bowser called outlaws, but he continued. "Just in time for me to squish you into little pieces!" said Bowser with a grin on his face as he walked over to a container. Inside it were two grand stars he swiped before having himself be defeated by Mario.
"Huh, I thought we had stopped you from getting those!"
"Oh, but you think wrong, for I swiped these away in time to have them in good use! And right now is a good time! But why don't we go to my newly installed arena above us in the sky for our upcoming battle?"
"Um, ok! Because Spike would hate to see the castle destroyed."
"Why don't we go now?" asked Bowser as he lunged towards them, and without warning, they were on their way to the arena through a portal of light. Many could see it miles away, what they won't see is the battle itself.
Yoshi and Spike landed on a huge land mass, where Bowser was floating around them, that's when he swallowed the first grand star. Purple beams of magic floated around him as he grew bigger and bigger. Until he was as big as a fortress. "Hey guess what guys?! Bowser called, his fist holding dark magic. "Your on a planet above Canterlot! We are accordingly a few meters above the castle, but high enough for my arena!" That's when he started moving above Yoshi and Spike, he then pulled back his dark magic filled fist.
"Spike!!! Jump For It!!!!!!!" When they jumped, Bowser's fist had hit the ground and streams of dark magic spilled out of his fist.
"Bowser! I thought you learned a lesson about this!!!!!!"
"But it's so much fun! But if you insist, we'll move on to my favorite technique on squishing your faces, for this will be the end." Bowser then swallowed the second grand star, that's when he got even bigger and bigger, so big that he almost destroyed the arena.
"Guess what Yoshi, you may think this is over, but it's far from over now I'm twice the size I was!" Twice the size? More like three times the size from before, but that was only half the problem, he was even destroying his arena!
Yoshi and Spike had no other choice but to jump at Bowser. That's when he destroyed the rest of the arena with his fists of Dark magic. Soon all three of them had started to fall back down to the castle, Bowser was so big he destroyed some of the castle's towers. Causing the castle to catch on fire, in the throne room, where Bowser Jr. and the soldiers were, had then decided to wait outside of the castle for the battle to end.
"Arghhh, my head, huh?!" Yoshi and Spike noticed Bowser, he was still wanting the battle to rage on. "Give up?"
"No Bowser, we will fight until you are defeated!"
"We'll see if that was the smarter choice fellas!" Bowser then started breathing out fire streams, he soon started firing fireballs, soon the throne room was completely on fire.
Soon Bowser started using his dark magics to form weapons against Yoshi and Spike, homing bullet bill launchers mostly. When he fired the bullet bills, Yoshi and Spike dodged them so flawlessly that when the bullet bills turned around, they had hit Bowser in the face.
"Ow!"
"Surrender Bowser!"
"You misunderstand, the fight is far from over!" Soon, he started throwing balls of dark magic at them, when it hits the ground, a black reddish crystal forms from the ground, the balls of dark magic kept coming, but Yoshi and Spike were able to dodge it with ease. Soon Bowser was out of ammo, and it was in a matter of time before Bowser would be defeated and the princesses can return.
Yoshi stepped towards the frightened tyrant. "Bowser, there's nowhere to run, or hide, you have no more things to use against us, so surrender and let the ponies of Equestria go free or die!"
Knowing he was staring at his death if he made the wrong decision, he tried to bribe Yoshi. "Here's a deal, I'll leave the place, but Equestria will still be mine to rule unless you get the princesses back, so all the ponies that were my slaves to begin with, which is basically all of them except the royal guard, will not be free when I still have control, they will come back to my home country with me and my son and soldiers, where they will toil for the rest of their pitiful lives, the princesses will also remain with the koopa kids. But since you wiped out the koopas in Equestria, we'll not step foot in this country again, and everything will return to normal."
Soon he began to undo his changes to Equestria, and built transportation airships to travel the slaves back home, he then returned everything to normal, except when he left, he left with all the other ponies asleep on his airships, for he also made it night when they left, the only things he did leave behind that were living creatures were the royal guard, and Yoshi and Spike.
Yoshi and Spike were extremely confused of what happened, but soon realized that they had the princesses and Ponies to save, they were glad to have the entire royal guard with them, they soon marched towards the lava world where Bowser lives in, and his gigantic castle where he kept the princesses.